一株耐锌细菌Sphingobacterium caeni S3的Zn2+吸附特征

Zinc adsorption characteristics of a zinc-resistant bacterium Sphingobacterium caeni S3

以一株耐锌细菌S3为研究对象,对其菌体及其胞外聚合物(EPS)的Zn^2+吸附特征进行研究.结果表明,菌株S3属于鞘氨醇杆菌属(Sphingobacterium),其序列与S.caeni相似性达到99%.Zn^2+对菌株S3生长的最小抑制浓度为500 mg·L^-1左右.S3活性菌体对Zn^2+的吸附率明显高于非活性菌体,且活性菌体实现吸附平衡的时间稍长.参与S3菌体Zn^2+吸附过程的官能团主要有缔合O-H、N-H和多糖的C-O.菌体EPS对Zn^2+的吸附率随时间延长逐渐增大,在80 min达到吸附平衡.S3菌体及EPS对Zn^2+的吸附过程均可采用准二级动力学模型进行描述.

A zinc-resistant strain S3 was investigated in terms of Zn^2+adsorption characteritics and extracellular polymeric substance(EPS).The results showed that strain S3 belongs to Sphingobacterium and shared a sequence similarity of 99%with S.caeni(acces-sion number:NR-109661.1).The minimum inhibitory concentration of Zn^2+to strain S3 was about 500 mg·L^-1.Zn^2+adsorption rate of the active strain was higher than that of the inactive strain,and the active bacteria displayed a relatively long adsorption equi-librium time.During the process of Zn^2+adsorption,O-H,N-H and C-O were the main functional groups of strain S3.Zn^2+adsorp-tion rate of bacterial EPS increased with time,with the adsorption equilibrium starting from 80 min.Zn^2+adsorption process of bacte-rial cell and EPS could be described by the pseudo-second-order kinetic model.